An organic light emitting device is a device in which a thin film including a fluorescent light emitting organic compound or a phosphorescent light emitting organic compound is interposed between an anode and a cathode. Further, electrons and holes are injected from the respective electrodes to generate excitons of the fluorescent light emitting organic compound or the phosphorescent light emitting organic compound, and the organic light emitting device emits light when the excitons return to the ground state.
Recent progress of an organic light emitting device is remarkable, and the organic light emitting device is characterized by, for example, exhibiting high luminance at a low applied voltage, having various emission wavelengths, exhibiting high-speed responsiveness, and allowing a light emitting device to be thinned and lightened. This suggests that the organic light emitting device may be used for a wide variety of applications.
However, the present situation requires optical output with even higher luminance or higher conversion efficiency. In addition, many problems still remain to be solved regarding durability against the change over time due to long-term use, and deterioration caused by atmospheric gas containing oxygen, moisture, or the like, for example. Further, taking applications for a full color display and the like into consideration, it is necessary to emit blue, green, or red light with a high color purity, but such problem has not been sufficiently solved yet.
In view of the foregoing, many studies have been conducted on various fused polycyclic aromatic compounds as light emitting organic compounds for forming an emission layer or the like. However, a compound having sufficiently satisfactory emission luminance and durability has hardly been obtained.
For example, bisanthracene derivatives (Japanese Patent Application Laid-Open No. 2000-344691) and chrysene derivatives (Japanese Patent Application Laid-Open No. 2004-75567 and Japanese Patent Application Laid-Open No. 2006-52323) have been disclosed as the fused polycyclic aromatic compounds. In particular, Japanese Patent Application Laid-Open No. 2006-52323 discloses that a bichrysene compound is used in the emission layer of an organic light emitting device, and describes specific compounds for a 5,5′-bichrysene compound and a 6,6′-bichrysene compound. In addition, the document describes merely unsubstituted bichrysenes such as 2,2′-bichrysene for nineteen kinds of isomers except the foregoing.